The present invention relates to testing radio frequency communication devices, such as wireless packet data transceivers, and in particular, to such devices that employ multiple radio acquisition technologies (RATs), such as “smartphones” and tablet computers, among others.
Today's more advanced wireless devices often include means (e.g., hardware, firmware and/or software components as appropriate) for uploading and downloading data via broadband cellular networks, and will typically need to use at least two different radio access technologies that permit such devices to connect with whatever cellular radio access technology is within range and available. For example, a device designed to provide internet access via a third generation (3G) RAT will also be capable of accessing a second generation (2G) RAT if a 3G RAT cellular network is unavailable or out of range. Newer devices designed for fourth generation (4G) RAT access may have two or more additional RATs that allow it to refer to 3G or 2G RAT as necessary, depending upon range and availability. By having these additional resources, i.e., capabilities of accessing multiple RATs, such devices ensure that users will be able to access cellular networks from more locations and with the fastest service possible.
Such devices having multiple RAT capabilities must be tested accordingly to ensure that all such RATs can be tested and verified as meeting the operational specifications prescribed for its corresponding signal standard, and has not been subject to design or manufacturing defects that render its operation out of such prescribed limits.
When such devices and their RATs are calibrated and tested, it is typically done in a sequential fashion. In other words, a test system is set up to calibrate one specific RAT for the device and to verify that the device operation using such RAT meets the prescribed standard specifications. The device is then prompted to transmit one or more signals, which are used to calibrate and verify that this particular RAT, as exercised in this device under test (DUT), operates in accordance with the prescribed standard specifications. Following that first calibration and/or verification test, the tester is then set up to do a similar calibration and verification by having the DUT operate using another RAT. As before, the DUT is prompted to send signals to the tester in accordance with this other RAT standard specification. If the DUT is capable of operating in accordance with more than two RATs, then, following the second calibration and test, a third calibration and test operation is set up by the tester and the DUT is once again prompted to send one or more signals in accordance with this third RAT. This process is repeated for all RATs of which the DUT is capable of using.
Such calibration and verification processes take a finite amount of time for each RAT. Additionally, time to set up the tester following each test or set of tests for the next test or set of tests, and time necessary to prompt the DUT to send the appropriate signals in accordance with the RAT to be tested all add potentially significant amounts of time to the setup and test duration, as well as multiple test command and control sequences. Accordingly, as devices become capable of operating in accordance with more RATs, the time and, therefore, cost, of testing such devices rises as well.